Supervisor with bad attitude

I went into FNB (Riversquare branch- 3 Rivers) to change an error on my account. The consultant (Santjie) could not assist me so she asked her supervisor (Hessie) for assistance. The supervisor Hessie showed attitude since the beginning and i could see she had no intention of trying to help me in the first place. All they kept saying was "Our system does not allow us to change your details) All i asked was for a letter of confirmation to say their system does not allow and yet again they were unable to help me with even a letter. Being frustrated with the mediocre performance i said "if you cannot help me then please close my account" Suprisingly Hessie rep**** "sure no problem we will close your account" With absolutely no care of losing a customer!! I then asked to see the manager The consultant (Santjie) then said she is the manager pointing at (Hessie) i said NO you told me shes the supervisor i need to see the manager.. then only she proceeded to call the manager (Engela jones) * Note how Santjie had **** to me initially. I explained my issue to Engela and without hesitation i was provided with the letter i had asked for. Why is Hessie (being a supervisor) *********** in her field and also willing to loose customers?? Im very disapointed in this service im really thinking of closing my account with FNB